Kanta moves from an urban environment to live with his uncle in the remote mountains of Hokkaido, northern Japan, due to his parents' work obligations. They believe exposure to nature will build his resilience, as he arrives displaying pronounced timidity and lacking peer companionship.

His isolation shifts when he encounters Poyu, an orphaned fawn whose parents and herd fell victim to hunters. Kanta forms a deep bond with the deer during the harsh Hokkaido winter. This evolving connection forces him to confront external threats, particularly hunters targeting the local deer population.

Through this journey, Kanta transitions from a reserved and apprehensive child into a figure of determination and bravery. His commitment to safeguarding Poyu and the broader deer community becomes central, fueled by a growing reverence for wildlife and understanding of their struggle for survival.

His experiences foster a profound respect for nature and a resolve to oppose practices endangering animals. He collaborates with Poyu to combat the deer's extinction, an effort that bolsters the deer's resilience and catalyzes Kanta's internal growth, solidifying themes of empathy, ecological responsibility, and personal fortitude.

One source notes he resides with his grandfather, though the majority specify his uncle as his guardian during this period.